1、Designation: F 1952 09An American National StandardStandard Specification forHelmets Used for Downhill Mountain Bicycle Racing1This standard is issued under the fixed designation F 1952; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revisi
2、on, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This specification covers performance requirements forhelmets used by downhill mountain bicycle riders
3、. Studieshave shown higher risk to the head and face for this sport ascompared to recreational street riding; hence, this specificationrequires greater impact protection and provides performancecriteria for chin bars on full-face helmets, but does not requirefull-face helmets. This specification rec
4、ognizes the desirabilityof lightweight construction and ventilation; however, it is aperformance specification and is not intended to restrict design.1.2 All testing and requirements of this specification shallbe in accordance with Test Methods F 1446, except wherenoted herein.1.3 Partial utilizatio
5、n of this standard is prohibited. Anystatement of compliance with this specification must be acertification that the product meets all of the requirements ofthis specification in its entirety. A product that fails to meet anyone of the requirements of this specification is considered tohave failed t
6、his standard, and should not be sold with anyindication that it meets parts of this standard.1.4 Headgear designed to comply with this and otherstandards may proclaim uses as certified by the manufacturer.1.5 The values stated in SI units are to be regarded asstandard. No other units of measurement
7、are included in thisstandard.1.6 This standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations
8、 prior to use.2. Referenced Documents2.1 ASTM Standards:2F 1446 Test Methods for Equipment and Procedures Usedin Evaluating the Performance Characteristics of ProtectiveHeadgear3. Labels and Warnings3.1 Shall meet the requirements of Test Methods F 1446.3.2 Shall have the words “For downhill mountai
9、n bicycleracing.”4. Marking the Test Line4.1 The test line is shown in Fig. 1 and shall be marked inaccordance with Test Methods F 1446.5. Conditioning and Number of Samples5.1 Shall be in accordance with Test Methods F 1446.6. Retention System Testing6.1 Retention system tests shall be performed be
10、fore impacttesting.6.2 The ambient helmet shall be subjected to the positionalstability (roll-off) test in accordance with Test Methods F 1446using a 4-kg drop mass from a height of 0.6 m.6.3 The hot, cold, and wet helmets shall be subjected to thedynamic strength retention test in accordance with T
11、est Meth-ods F 1446 using a 4-kg drop mass from a height of 0.6 m.6.4 The retention system shall remain intact without elon-gating more than 30 mm.7. Impact Sites and Projections7.1 Impact sites are described in Test Methods F 1446.1This specification is under the jurisdiction of ASTM Committee F08
12、on SportsEquipment and Facilities and is the direct responsibility of Subcommittee F08.53 onHeadgear and Helmets.Current edition approved Jan. 1, 2009. Published February 2009. Originallyapproved in 1999. Last previous edition approved in 2000 as F 1952 00.2For referenced ASTM standards, visit the A
13、STM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, Uni
14、ted States.7.2 ProjectionsAny unfaired projection extending morethan 7 mm from the helmets outer surface shall break away orcollapse when impacted with forces equivalent to those pro-duced by applicable impact-attenuation tests described inSection 9.7.2.1 There shall be no fixture on the helmets inn
15、er surfaceprojecting more than 2 mm into the helmet interior exceptoccipital stabilizers and foam fit pads.8. Impacting Schedule8.1 All impacting shall be performed in accordance withTest Methods F 1446.8.2 Helmets shall be impacted with the anvils centered on orabove the test line described in Fig.
16、 1.8.3 The test anvils can be oriented in any horizontal,centered position.HEADFORM DIMENSIONSIZE X L/2 Y R S T UA 24.0 88.0 89.7 47.5 23.0 142.0 84.0E 26.0 94.5 96.0 49.0 24.0 151.0 88.0J 27.5 101.0 102.5 50.5 25.0 160.0 92.0M 29.0 106.0 107.0 52.0 27.0 166.0 96.0O 30.0 108.5 110.0 53.0 27.0 170.0
17、97.0FIG. 1 Marking the Test LineF19520928.4 For full face helmets with a chin bar, a fifth ambienthelmet shall be tested in accordance with Section 10.9. Impact Testing9.1 Retention system testing shall be completed prior toimpact testing.9.2 The helmet can be impacted such that the theoreticalcente
18、r of impact described in Test Methods F 1446 is anywhereon or above the test line with the curbstone anvil in anyhorizontal orientation.9.3 Anvils to be used are the flat, hemispherical, andcurbstone anvils in Test Methods F 1446.9.4 The helmet shall be dropped onto the flat anvil toachieve an impac
19、t velocity of 6.2 m/s 6 3 % (corresponding toa theoretical drop height of 2.0 m).9.5 The helmet shall be dropped onto the hemispherical andcurbstone anvils to achieve an impact velocity of 5.6 m/s 63 % (corresponding to a theoretical drop height of 1.6 m).9.6 Each helmet shall be given two flat anvi
20、l impacts andone each hemispherical and curbstone anvil impact in anysequence.9.7 The theorretical center of each impact site shall beseparated from the theoretical center of other impact sites by aminimum of 120 mm.9.8 The peak acceleration of each impact shall not exceed300 g.10. Chin Bar Rigidity
21、 Test10.1 The chin bar rigidity test applies to helmets with a chinbar only.10.2 If a chin bar is present, it shall be tested in accordancewith the procedures in Test Methods F 1446, Chin Bar RigidityTest, with an impact velocity of 2.8 m/s 6 5 % (correspondingto a theoretical drop height of 0.4 m),
22、 using a fifth ambientsample that has not been subjected to any other impact testing.The maximum deflection of the chin bar shall not exceed60 mm.11. Keywords11.1 bicycle; downhill; helmets; mountain; racingASTM International takes no position respecting the validity of any patent rights asserted in
23、 connection with any item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the re
24、sponsible technical committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive care
25、ful consideration at a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM Internationa
26、l, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F1952093
